In recent years endoscopes capable of viewing a patient or test subject have been widely employed. An endoscope can observe organs or other structures. Further, an endoscope can be used for providing therapeutic treatments or surgical interventions by inserting treatment tools into a treatment tool channel provided therein. A typical example of this would be a rigid endoscope including a hard insertion section, which incorporates an image capturing device. With this rigid endoscope, a light guide cable and a scope cable are integrated within the rigid endoscope main body. Flexible endoscopes may also be used to observe anatomic structures. Many different types of electronic endoscopes using a solid state imaging device such as a charge coupled device (CCD) or complementary metal-oxide-semiconductor sensor (CMOS) as imaging means have also been considered and/or used.
However, certain anatomical structures are difficult to observe in conventional endoscopes under normal visible lighting conditions. For example, the common bile duct is not infrequently damaged in laparoscopic resection of the gallbladder because of its size, location and visual perception limitations inherent in endoscopic surgical techniques (Way L W, Stewart L, Gantert W, Liu K, Lee C M, Whang K, Hunter J G. “Causes and prevention of laparoscopic bile duct injuries: analysis of 252 cases from a human factors and cognitive psychology perspective.” Annals of Surgery 2003 April; 237(4):460-9). Similarly, the ureter can be damaged in surgery, especially in pelvic operations. Although these injuries can be repaired, they may not be apparent until after the conclusion of the procedure. Commonly in the case of the bile duct, infusion of the duct structures with an X-ray contrast agent may be performed, and an X-ray photograph or fluoroscopic image is taken in the form of an intraoperative cholangiogram. This necessitates stopping the surgical procedure and requires bringing an X-ray machine into the operating theater. Furthermore, the operator and assistants must put on lead gowns making this procedure inconvenient and time consuming. For this reason, many surgeons may be resistant to this X-ray examination. An extensive review on the role of intraoperative cholangiography in avoiding bile duct injury the data suggest that the use and correct interpretation of IOC decreases the rate of common bile duct injury and that its broader use will improve patient safety (Massarweh N N, Flum D R. (2007). “Role of intraoperative cholangiography in avoiding bile duct injury.” Journal American College Surgery 204(4):656-64. However, selective intraoperative cholangiography as compared to routine intraoperative cholangiography (IOC) techniques in itself increases the risk of injury to the common bile duct (Flum D R, Dellinger E P, Cheadle A, Chan L, Koepsell T (2003) “Intraoperative cholangiography and risk of common bile duct injury during cholecystectomy.” Journal American Medical Association 289(13):1639-44).
As described in more detail herein, the present invention provides for bioluminescent endoscopy methods, and compounds for use in bioluminescent endoscopy, to avoid such problems in surgery. However, and potentially much more significantly, the present invention also has a significant use in the detection and treatment of cancer, including specifically, breast cancer and melanoma.
Radical mastectomy was first demonstrated nearly 100 years ago by Halstead as a potentially effective surgical response to breast cancer. Fifty years later, Patey proved that modified radical mastectomy could yield similar survival with limited morbidity. Since the time of Halstead to the current day, the status of the regional nodal basin remains the single most important independent variable in predicting prognosis. Advocates of axillary dissection contend that there is a benefit for breast cancer patients because axillary dissection provides direct regional control of axillary disease. Axillary lymph node dissection (ALND) provides excellent regional tumor control, and the pathologic information gained is pivotal to the planning of adjuvant therapy. Axillary lymph node metastasis in patients with early breast cancer is the single most important prognostic factor for recurrence and survival and forms the basis for important therapeutic decisions. Critics of axillary dissection maintain that overall survival depends on the development of distant metastases and is not influenced by axillary dissection in most patients. They contend that patients with microscopic axillary metastases might be cured with adjuvant chemotherapy with or without nodal irradiation in the absence of axillary dissection. Many have even advocated abandoning axillary dissection in early breast cancer. Axillary lymph node dissection is a major operation; ALND is associated with acute complication rates of 20% to 30% and chronic lymphedema rates of 7% to 37%. The majority of women who undergo ALND for breast cancer experience enduring surgery-related symptoms such as scarring, pain, numbness, lymphedema and weakness and stiffness of the ipsilateral arm and shoulder, as well as decreased sweat production in the distribution of the intercostobrachial nerve. Postoperative studies have shown that the degree of total pain was significantly associated with the number of lymph nodes dissected. These controversies have been amplified by the fact that the fundamental biology of lymphatic metastasis remains poorly understood. There is as yet an incomplete understanding of functional lymphatic biology, and a general lack of appropriate experimental models (Tanis, P. J., M. C. van Rijk, et al. (2005). “The posterior lymphatic network of the breast rediscovered.” Journal of Surgical Oncology 91(3): 195-8.; Barrett, T., P. L. Choyke, et al. (2006). “Imaging of the lymphatic system: new horizons.” Contrast Media & Molecular Imaging 1(6): 230-45.; Estourgie, S. H., O. E. Nieweg, et al. (2004). “Lymphatic drainage patterns from the breast. [see comment].” Annals of Surgery 239(2): 232-7.)
Systematic studies in breast cancer have shown that breast cancer spreads via the lymphatic system to one or a few lymph nodes before it spreads to other axillary nodes. These first affected lymph nodes are often labeled as “sentinel lymph node(s)” (SLNs), Sentinel-lymph-node biopsy (SNB) was developed for the axillary staging of breast carcinoma. See Chetty, U., P. K. Chin, et al. (2008). “Combination blue dye sentinel lymph node biopsy and axillary node sampling: the Edinburgh experience.” European Journal of Surgical Oncology 34(1): 13-6.; Christiansen, P., E. Friis, et al. (2008). “Sentinel node biopsy in breast cancer: five years experience from Denmark.” Acta Oncologica 47(4): 561-8.; Cochran, A. J., S. J. Ohsie, et al. (2008). “Pathobiology of the sentinel node.” Current Opinion in Oncology 20(2): 190-5.; Fenaroli, P., M. Merson, et al. (2004). “Population-based sentinel lymph node biopsy in early invasive breast cancer.” European Journal of Surgical Oncology 30(6): 618-23.
If the SLN does not contain metastasis, then patients and surgeons may choose to delay or omit ALND, with a favorable effect on patients' quality of life. Despite few controlled clinical studies of SNB, this procedure has become widely practiced in the United States, Europe, and Australia. Currently, at most major cancer centers in the United States, SNB is performed without ALND if no disease is found in the SLN. (Bankhead, C. (2007). “Debate over sentinel node biopsy continues.” Journal of the National Cancer Institute 99(10): 751-3.) The American Society of Clinical Oncology (ASCO) officially supports the use of SNB for staging disease in most women with clinically negative axillary lymph nodes. They continue to recommend routine ALND for patients with a positive SLN according to routine histopathological examination. (Lyman, G. H., A. E. Giuliano, et al. (2005). “American Society of Clinical Oncology guideline recommendations for sentinel lymph node biopsy in early-stage breast cancer. [see comment].” Journal of Clinical Oncology 23(30): 7703-20.) SNB is not recommended for large or locally advanced invasive breast cancers (Boileau, J. F., A. Easson, et al. (2008). “Sentinel nodes in breast cancer: relevance of axillary level II nodes and optimal number of nodes that need to be removed.” Annals of Surgical Oncology 15(6): 1710-6.)
The SNL biopsy is typically evaluated by classical staining methods, or preferably in combination with the immunohistochemical staining of lymph nodes. The histological status of the axillary nodes remains the single best predictor of survival in patients with breast cancer. Ideally, the SNL biopsy would involve intraoperative frozen-section examination, involving complete sectioning of the entire lymph node and examination of a large number of sections. Unfortunately, until quite recently this has been difficult to perform in the intraoperative setting in a definitive manner, and even now, rapid immunohistochemical analysis of the sections remains difficult.
Therefore, various methods for lymphatic imaging have been used during the interoperative procedures. Lymphatic connection with the tumor can be identified by using Lymphazurin vital blue dye, various other vital stains, a radiolabeled colloid, or a combination thereof. Indeed, the greatest proportion of successful mappings and the lowest false-negative rates were associated with studies in which both blue dye and radiolabeled colloid were used. (Kitai, T., T. Inomoto, et al. (2005). “Fluorescence navigation with indocyanine green for detecting sentinel lymph nodes in breast cancer.” Breast Cancer 12(3): 211-5.; Koizumi, M., E. Nomura, et al. (2004). “Radioguided sentinel node detection in breast cancer patients: comparison of 99 mTc phytate and 99mTc rhenium colloid efficacy.” Nuclear Medicine Communications 25(10): 1031-7.; Anan, K., S. Mitsuyama, et al. (2006). “Double mapping with subareolar blue dye and peritumoral green dye injections decreases the false-negative rate of dye-only sentinel node biopsy for early breast cancer: 2-site injection is more accurate than 1-site injection. [see comment].” Surgery 139(5): 624-9; Lin, K. M., T. H. Patel, et al. (2004). “Intradermal radioisotope is superior to peritumoral blue dye or radioisotope in identifying breast cancer sentinel nodes.” Journal of the American College of Surgeons 199(4): 561-6; Mariani, G., P. Erba, et al. (2004).; “Lymphoscintigraphic and intraoperative detection of the sentinel lymph node in breast cancer patients: the nuclear medicine perspective.” Journal of Surgical Oncology 85(3): 112-22.; Nour, A. (2004). “Efficacy of methylene blue dye in localization of sentinel lymph node in breast cancer patients.” Breast Journal 10(5): 388-91;
In some medical centers, lymphoscintigraphic imaging using a gamma camera is routinely performed before intraoperative probe detection of radioactivity in sentinel nodes at surgery for axillary staging of breast cancer, typically with 99mTc sulfur colloid agents. This is not always easy to do. There is substantial variability in the frequency of imaging visualization of internal mammary nodes, ranging from under 10% to nearly 40% in some series. See Celebioglu, F., L. Perbeck, et al. (2007). “Lymph drainage studied by lymphoscintigraphy in the arms after sentinel node biopsy compared with axillary lymph node dissection following conservative breast cancer surgery.” Acta Radiologica 48(5): 488-95.). PET scanning has been employed (Zornoza, G., M. J. Garcia-Velloso, et al. (2004). “18F-FDG PET complemented with sentinel lymph node biopsy in the detection of axillary involvement in breast cancer.” European Journal of Surgical Oncology 30(1): 15-9). The frequency of internal mammary nodal visualization may be dependent on the type of colloid used and route of injection as well as the time from imaging until injection (Barranger, E., A. Cortez, et al. (2004). “Laparoscopic sentinel node procedure using a combination of patent blue and radiocolloid in women with endometrial cancer.” Annals of Surgical Oncology 11(3): 344-9.; Barranger, E., K. Kerrou, et al. (2007). “Place of a hand-held gamma camera (POCI) in the breast cancer sentinel node biopsy.” Breast 16(5): 443-4.)
In SNB, pathologists receive either single lymph nodes dissected free of fat or axillary fat containing one or more lymph nodes. Fatty nodules are carefully dissected to identify all lymph nodes. Lymph nodes are inspected for blue dye color, if such dye has been used, measured, and cut into sections generally no thicker than 2.0 mm through and parallel to the longest meridian. Each SLN is submitted in a separate cassette or identified by colored ink to permit accurate assessment of the total number of lymph nodes and number of involved lymph nodes; all node sections are submitted for microscopic examination. Radioactivity is quantified in the samples in each cassette if a radioactive tracer has been used.
The sentinel node concept has also been validated in malignant melanoma (Chakera, A. H., K. T. Drzewiecki, et al. (2004). “Sentinel node biopsy for melanoma: a study of 241 patients.” Melanoma Research 14(6): 521-6; Gipponi, M., C. Di Somma, et al. (2004). “Sentinel lymph node biopsy in patients with Stage I/II melanoma: Clinical experience and literature review.” Journal of Surgical Oncology 85(3): 133-40. Essner, R. (2006). “Experimental frontiers for clinical applications: novel approaches to understanding mechanisms of lymph node metastases in melanoma.” Cancer & Metastasis Reviews 25(2): 257-67).
The sentinel node concept has potential application in other types of cancer, due to the known fact that the lymphatic system serves as a primary route for the dissemination of many solid tumors, particularly those of epithelial origin including colon and prostate. The feasibility and diagnostic reliability of sentinel node mapping of lung cancers is currently under study by a number of investigators. (Bustos, M. E., J. J. Camargo, et al. (2008). “Intraoperative detection of sentinel lymph nodes using Patent Blue V in non-small cell lung cancer.” Minerva Chirurgica 63(1): 29-36.), gynecological (Ayhan, A., H. Celik, et al. (2008). “Lymphatic mapping and sentinel node biopsy in gynecological cancers: a critical review of the literature.” World Journal of Surgical Oncology 6: 53) and gastrointestinal cancers (Arigami, T., S, Natsugoe, et al. (2006). “Evaluation of sentinel node concept in gastric cancer based on lymph node micrometastasis determined by reverse transcription-polymerase chain Mutter, D., F. Rubino, et al. (2004). “A new device for sentinel node detection in laparoscopic colon resection.” Journal of the Society of Laparoendoscopic Surgeons 8(4): 347-51. Mayinger, B. (2004). “Endoscopic fluorescence spectroscopic imaging in the gastrointestinal tract.” Gastrointestinal Endoscopy Clinics of North America 14(3): 487-505.; Mayinger, B., M. Jordan, et al. (2004). “Evaluation of in vivo endoscopic autofluorescence spectroscopy in gastric cancer.” Gastrointestinal Endoscopy 59(2): 191-8. Ishizaki, M., A. Kurita, et al. (2006). “Evaluation of sentinel node identification with isosulfan blue in gastric cancer.” European Journal of Surgical Oncology 32(2): 191-6.; Ishikawa, K., K. Yasuda, et al. (2007). “Laparoscopic sentinel node navigation achieved by infrared ray electronic endoscopy system in patients with gastric cancer.” Surgical Endoscopy 21(7): 1131-4).